Eyeglasses, which are intended to correct a person's vision to normal or near-normal, and safety glasses, which are intended to protect a person's eyes from harm, have been known for centuries. Both types of eyewear typically rest on the nose, and on each ear of a person. A person's perception of how well a pair of glasses fit is influenced primarily by how well the glasses fit on the nose and over the ears, perhaps together with whether the lenses of the glasses are too close to the person's eyes or face, or other factors.
One method used to improve the fit of glasses is to provide two nose pads, one of which contacts each side of a person's nose, and to mount each nose pad on a small, flexible spring or wire referred to as a pad arm. The pad arm can then be permanently deformed by an optical professional so that each nose pad contacts its respective side of the person's nose at an acceptable position. If a person puts on the glasses in a slightly different manner, or in a slightly different location, the pad arm can resiliently deform to provide minor but automatic adjustments in use.
Glasses with pad arm nose pads are widely used, but they have some known problems. First, they are more expensive than fixed nose-bridge glasses, which can be mass-produced with a pad or pads at predetermined positions. Second, they typically require that an optical professional spend several minutes making manual adjustments to the pad arms before they can be given to a person for use, which increases the staffing requirements and costs of the optical business. Third, if the glasses are struck or crushed, the spring or wire pad arm supporting a nose pad may be permanently deformed, which typically requires the wearer to return to the office of an optical professional to have the glasses fixed and re-fit.
Glasses with fixed nose bridges have also been widely used, in particular, as sun glasses or safety glasses. The fixed nose bridge is designed to fit a typical person's nose, and although the fit may not be highly satisfactory, the cost of the glasses is often low enough that users are willing to trade comfort for cost-savings. However, it would be desirable to provide glasses for a person that provide an improved fit, particularly in the nose area, without increasing the costs of the glasses or requiring manual adjustments by an optical professional.
Certain prior techniques for attempting to improve the fit of certain types of glasses are described in U.S. Pat. No. 4,762,407 (Anger et al.), U.S. Pat. No. 6,074,058 (Anger), and U.S. Pat. No. 7,648,235 (Rosenfield).